DataSource (Java EE 5 SDK)

javax.activation Interface DataSource

所有已知子接口:

MultipartDataSource

所有已知实现子孙类:

ByteArrayDataSource, FileDataSource, MimePartDataSource, URLDataSource

public interface DataSource

The DataSource interface provides the JavaBeans Activation Framework with an abstraction of an arbitrary collection of data. It provides a type for that data as well as access to it in the form of InputStreams and OutputStreams where appropriate.

getInputStream

InputStream getInputStream()
                           throws IOException

This method returns an InputStream representing the data and throws the appropriate exception if it can not do so. Note that a new InputStream object must be returned each time this method is called, and the stream must be positioned at the beginning of the data.

返回:

an InputStream

抛出异常:

IOException

getOutputStream

OutputStream getOutputStream()
                             throws IOException

This method returns an OutputStream where the data can be written and throws the appropriate exception if it can not do so. Note that a new OutputStream object must be returned each time this method is called, and the stream must be positioned at the location the data is to be written.

返回:

an OutputStream

抛出异常:

IOException

getContentType

String getContentType()

This method returns the MIME type of the data in the form of a string. It should always return a valid type. It is suggested that getContentType return "application/octet-stream" if the DataSource implementation can not determine the data type.

返回:

the MIME Type

getName

String getName()

Return the name of this object where the name of the object is dependant on the nature of the underlying objects. DataSources encapsulating files may choose to return the filename of the object. (Typically this would be the last component of the filename, not an entire pathname.)

返回:

the name of the object.

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